Community Water System · PWS 105300027
Chehalis Tribal Housing
Operator location Oakville, EPA Region 10 — Tribal Water Systems - 0% of 299 violations are health-based (lower-third health share (≤ 1%)); groundwater source; 620 served per SDWIS.
- 620
- People served (this PWS)
- 299
- EPA violations (this PWS)
- 1
- Health-based (this PWS)
- Untested
- UCMR5 (this PWS)
Chehalis Tribal Housing standing, high SDWIS violation third
0% of 299 recorded violations are health-based - lower-third health share (≤ 1%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 0% is lower-third health share (≤ 1%). Population rank #25,761 of 29,740 among systems serving 500+.
The verdict
Chehalis Tribal Housing sits in the upper third of the sitemap cohort by violation count (299), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (620; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is only 0% - almost all of this trail is monitoring or reporting. No UCMR5 PFAS test appears for this system in this extract.
- #25,761 of 29,740
- Population · /systems
- #44 of 52
- Population · 10
- 299
- Total EPA violations on record
- 0%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Native American
- Connections
- 114
- School/Daycare
- No
- MCL Violations
- 0
- Monitoring Violations
- 279
- Treatment Tech Violations
- 1
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Coliform (TCR) | MR | 36 | 2013 |
| Chlorine | MR | 25 | 2025 |
| Gross Alpha, Excl. Radon and U | MR | 17 | 2017 |
| Combined Uranium | MR | 16 | 2017 |
| Combined Radium (-226 and -228) | MR | 16 | 2017 |
| Nitrate | MR | 14 | 2024 |
| Consumer Confidence Rule | Other | 14 | 2017 |
| Total Polychlorinated Biphenyls (PCB) | MR | 5 | 2025 |
| TTHM | MR | 5 | 2023 |
| Total Haloacetic Acids (HAA5) | MR | 5 | 2023 |
| Lead and Copper Rule | MR | 4 | 2020 |
| Revised Total Coliform Rule | RPT | 4 | 2025 |
| 2,3,7,8-TCDD | MR | 3 | 2025 |
| Hexachlorocyclopentadiene | MR | 3 | 2025 |
| Atrazine | MR | 3 | 2025 |
| Heptachlor | MR | 3 | 2025 |
| HEXACHLOROBENZENE | MR | 3 | 2025 |
| Benzo(a)pyrene | MR | 3 | 2025 |
| Chlordane | MR | 3 | 2025 |
| Simazine | MR | 3 | 2025 |
| Toxaphene | MR | 3 | 2025 |
| Di(2-ethylhexyl) adipate | MR | 3 | 2025 |
| Methoxychlor | MR | 3 | 2025 |
| Di(2-ethylhexyl) phthalate | MR | 3 | 2025 |
| Endrin | MR | 3 | 2025 |
| Arsenic | MR | 3 | 2005 |
| LASSO | MR | 3 | 2025 |
| Heptachlor epoxide | MR | 3 | 2025 |
| BHC-GAMMA | MR | 3 | 2025 |
| Pentachlorophenol | MR | 2 | 2011 |
Violation Count vs. the National Corpus
Chehalis Tribal Housing has 299 recorded EPA violations, 91% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 9% carry more. 0% of this system's own violations are health-based (1 of 299), and it ranks #25,761 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
299 Higher than most more violations than 91% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
Health-based violations on Chehalis Tribal Housing
1 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for 105300027.
Sources: EPA SDWIS
Nationwide peers
299 violations · 620 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems with smaller service footprints
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Chehalis Tribal Housing
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in EPA Region 10 — Tribal Water Systems compares on the same EPA violation measures. EPA Region 10 — Tribal Water Systems systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.